Effect of linseed supplementation on fatty acid composition and lipid oxidation of Maremmana beef

The interest in feeding strategies aimed to increase the level of polyunsaturated fatty acid (PUFA) in animal products is growing. Linseed supplementation has been reported as an useful strategy in order to increase PUFAω-3 content. However, less knowledge is available about the effect of PUFAω-3 enrichment on the shelf life of meat. The aim of this work was to evaluate the intramuscular fat oxidative stability of beef obtained from Maremmana young bulls fed a diet supplemented with extruded linseed. 20 Maremmana young bulls were divided in 2 groups: experimental (E- diet supplemented with extruded linseed during fattening) and Control (C- diet without linseed) group. Longissimus dorsi muscles of each animal were sampled, grinded and stored at 4 °C. Fatty acid composition, cholesterol, peroxide, dienes, thiobarbituric acid reactive substances (TBARs), retinol, carotenoids, and cholesterol oxidation products (COPs) levels were determinated at 0, 2 and 6 days of storage. The linseed supplementation led to a significantly increase (+85%) of PUFA ω-3. E group’s beef showed a higher susceptibility to lipid oxidation: TBARs and COPs levels increased by 141% after 2 and 6 days respectively. On the contrary, retinol and carotenoids similarly decreased in beef from both groups. In conclusion, the beef from C group was more stable with regard to oxidation, probably due to the lower levels of pro-oxidant substances and to the proper content of antioxidant substances. In contrast, although the level of antioxidant substances at time 0 was similar between groups, the beef from E group showed a significant increase of oxidation products already after two days. These results suggested that linseed supplementation improves meat quality by increasing PUFAω-3 content, but higher levels of antioxidants than those normally present in the intramuscular fat are needed in order to control the oxidation during the storage.